RESUMEN
PURPOSE: To understand how the axial plane deformity contributes to progression of the three-dimensional spinal deformity of Adolescent Idiopathic Scoliosis (AIS), with a main thoracic curve type, using a series of sequential magnetic resonance images (MRI). METHODS: Twenty-seven AIS patients (at scan 1: mean 12.4 years (± 1.5), mean Cobb angle 29.1°(± 8.8°)) had 3 MRI scans (T4-L1) performed at intervals of mean 0.7 years (± 0.4). The outer profile of the superior and inferior endplates were traced on a reformatted axial image using ImageJ (NIH). Endplate AVR, and intravertebral rotation (IVR), defined as the difference between superior and inferior endplate AVR, was calculated for each vertebral level. RESULTS: For all patients and scans, the mean AVR was greatest at the curve apex, with AVR diminishing in a caudal and cephalic direction from the apex. At scan 3 the mean apical AVR was 15.1°(± 4.6°) with a mean change in apical AVR between MRI 1 and 3 of 2.7°(± 2.9°). The increase in standing height between MRI 1 and 3 was mean 7.4 cm (± 4.6). Linear regression showed a positive correlation between apical AVR and Cobb angle (R2 = 0.57, P < 0.001), and a positive correlation between apical AVR and rib hump (R2 = 0.54, p < 0.001). The mean change in IVR was greater 3 vertebral levels cephalic and caudal to the apex (1.4°(± 4.1°) and 1.2°(± 2.0°), respectively), compared to the apex (0.4°(± 3.1°)). CONCLUSIONS: AVR increased, during curve progression, most markedly at the curve apex. The greatest IVR was observed at the periapical levels, with the apex by contrast having only a modest degree of rotation, suggesting the periapical vertebral levels of the scoliosis deformity may be a significant driver in the progression of AIS.
Asunto(s)
Escoliosis , Humanos , Adolescente , Escoliosis/diagnóstico por imagen , Estatura , Modelos Lineales , Imagen por Resonancia Magnética , RotaciónRESUMEN
BACKGROUND: A new growing rod (GR) design, the semiconstrained growing rod (SCGR), with the added advantage of axial rotation freedom within the components, has been introduced at our center which has been shown to be growth friendly. We hypothesize that the SCGR system would reduce autofusion in vivo, thereby maximizing the coronal plane correction, T1-S1 growth, and the final correction achieved at definitive fusion for children with an early onset scoliosis. METHODS: In total, 28 patients had either single or dual 5.5 mm diameter SCGR placed minimally invasively through a submuscular approach. Surgical lengthening procedures occurred approximately every 6 months until the definitive fusion procedure was performed for 18 patients. Scoliosis, kyphosis, and lordosis angles, T1-S1 trunk length, and any complications encountered were evaluated. RESULTS: For the full cohort, before GR insertion, the mean major Cobb curve angle was 72.4 degrees (SD, 18.8; range, 45 to 120), mean T1-S1 trunk length was 282 mm (SD, 59; range, 129 to 365), and at the latest follow-up (mean 6.9 y, SD 3.3, range 2.0 to 13.0), 38.8 degrees (SD, 17.5; range 10 to 90) and 377 mm (SD, 62; range, 225 to 487), respectively. For the subset of 18 patients who have had their final instrumented fusion surgery, the definitive surgery procedure alone produced a correction of the major Cobb curve angle by mean 20.3 degrees (SD, 16.1; P<0.0001), and an increase in the T1-S1 trunk length of mean 31.7 mm (SD, 23.1; P<0.0001). There were 14 complications involving 11 of the 28 patients, giving rise to 5 unplanned surgical interventions and 1 case where GR treatment was abandoned. CONCLUSIONS: SCGR patients exhibited statistically significant increase in T1-S1 trunk length and statistically significant decrease in the severity of scoliosis over the course of GR treatment and again, importantly, with the definitive fusion surgery, suggesting that autofusion had been minimized during GR treatment with relatively low complication rates. LEVEL OF EVIDENCE: Level IV-case series.
Asunto(s)
Fijadores Internos , Implantación de Prótesis/métodos , Escoliosis/cirugía , Adolescente , Niño , Femenino , Humanos , Cifosis/cirugía , Masculino , Estudios Prospectivos , Radiografía , Estudios Retrospectivos , Escoliosis/diagnóstico por imagen , Fusión Vertebral , Columna Vertebral/crecimiento & desarrollo , Columna Vertebral/cirugía , Resultado del TratamientoRESUMEN
OBJECTIVE: To investigate whether growing rod surgery for children with progressive idiopathic early onset scoliosis (EOS) effects activity and participation, and investigate factors that may affect this. STUDY DESIGN: Multicenter retrospective cohort study using prospectively collected data on 60 children with idiopathic EOS and significant scoliosis (defined as a Cobb angle >40°). Thirty underwent brace treatment, and 30, growth rod surgery. Questionnaire and radiographic data were recorded at 1 year. The validated Activities Scale for Kids performance version (ASKp) questionnaire was used to measure activity and participation. RESULTS: In the brace group, Cobb angle increased from 60° to 68°. There was no change in ASKp score. In the operative group, Cobb angle decreased from 67° to 45°. ASKp decreased from 91 to 88 (P < .01). Presence of spinal pain correlated with greater reduction in activity and participation scores in both groups, as did occurrence of complications in the operative group (P < .05). Both treatments permitted growth of the immature spine. CONCLUSIONS: In children with significant idiopathic EOS (Cobb angle>40°), growth rod surgery was associated with a reduction in activity and participation and Cobb angle, whereas brace treatment was associated with an increase in Cobb angle and no change in activity and participation. Pain was the most important factor affecting activity and participation in both groups.
Asunto(s)
Tirantes/estadística & datos numéricos , Ejercicio Físico , Fijadores Internos/efectos adversos , Escoliosis/rehabilitación , Escoliosis/cirugía , Fusión Vertebral/métodos , Niño , Preescolar , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Crecimiento , Humanos , Masculino , Análisis Multivariante , Dimensión del Dolor/métodos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/fisiopatología , Radiografía Torácica/métodos , Estudios Retrospectivos , Escoliosis/diagnóstico por imagen , Índice de Severidad de la Enfermedad , Fusión Vertebral/efectos adversos , Estadísticas no Paramétricas , Resultado del TratamientoRESUMEN
BACKGROUND: Adolescent idiopathic scoliosis is a complex three-dimensional deformity of the spine characterized by deformities in the sagittal, coronal, and axial planes. Spinal fusion using pedicle screw instrumentation is a widely used method for surgical correction in severe (coronal deformity, Cobb angle > 45°) adolescent idiopathic scoliosis curves. Understanding the anatomic difference in the pedicles of patients with adolescent idiopathic scoliosis is essential to reduce the risk of neurovascular or visceral injury through pedicle screw misplacement. QUESTIONS/PURPOSES: To use CT scans (1) to analyze pedicle anatomy in the adolescent thoracic scoliotic spine comparing concave and convex pedicles and (2) to assess the intra- and interobserver reliability of these measurements to provide critical information to spine surgeons regarding size, length, and angle of projection. METHODS: Between 2007 and 2009, 27 patients with adolescent idiopathic scoliosis underwent thoracoscopic anterior correction surgery by two experienced spinal surgeons. Preoperatively, each patient underwent a CT scan as was their standard of care at that time. Twenty-two patients (mean age, 15.7 years; SD, 2.4 years; range, 11.6-22 years) (mean Cobb angle, 53°; SD, 5.3°; range, 42°-63°) were selected. Inclusion criteria were a clinical diagnosis of adolescent idiopathic scoliosis, female, and Lenke type 1 adolescent idiopathic scoliosis with the major curve confined to the thoracic spine. Using three-dimensional image analysis software, the pedicle width, inner cortical pedicle width, pedicle height, inner cortical pedicle height, pedicle length, chord length, transverse pedicle angle, and sagittal pedicle angles were measured. Randomly selected scans were remeasured by two of the authors and the reproducibility of the measurement definitions was validated through limit of agreement analysis. RESULTS: The concave pedicle widths were smaller compared with the convex pedicle widths at T7, T8, and T9 by 37% (3.44 mm ± 1.16 mm vs 4.72 mm ± 1.02 mm; p < 0.001; mean difference, 1.27 mm; 95% CI, 0.92 mm-1.62 mm), 32% (3.66 mm ± 1.00 mm vs 4.82 mm ± 1.10 mm; p < 0.001; mean difference, 1.16 mm; 95% CI, 0.84 mm-1.49 mm), and 25% (4.10 mm ± 1.57 mm vs 5.12 mm ± 1.17 mm; p < 0.001; mean difference, 1.02 mm; 95% CI, 0.66 mm-1.39 mm), respectively. The concave pedicle heights were smaller than the convex at T5 (9.43 mm ± 0.98 vs 10.63 mm ± 1.10 mm; p = 0.002; mean difference, 1.02 mm; 95% CI, 0.59 mm-1.45 mm), T6 (8.87 mm ± 1.37 mm vs 10.88 mm ± 0.81 mm; p < 0.001; mean difference, 2.02 mm; 95% CI, 1.40 mm-2.63 mm), T7 (9.09 mm ± 1.24 mm vs 11.35 mm ± 0.84 mm; p < 0.001; mean difference, 2.26 mm; 95% CI, 1.81 mm-2.72 mm), and T8 (10.11 mm ± 1.05 mm vs 11.86 mm ± 0.88 mm; p < 0.001; mean difference, 1.75 mm; 95% CI, 1.30 mm-2.19 mm). Conversely, the concave transverse pedicle angle was larger than the convex at levels T6 (11.37° ± 4.48° vs 8.82° ± 4.31°; p = 0.004; mean difference, 2.54°; 95% CI, 1.10°-3.99°), T7 (12.69° ± 5.93° vs 8.65° ± 3.79°; p = 0.002; mean difference, 4.04°; 95% CI, 1.90°-6.17°), T8 (13.24° ± 5.28° vs 7.66° ± 4.87°; p < 0.001; mean difference, 5.58°; 95% CI, 2.99°-8.17°), and T9 (19.95° ± 5.69° vs 8.21° ± 4.02°; p < 0.001; mean difference, 4.74°; 95% CI, 2.68°-6.80°), indicating a more posterolateral to anteromedial pedicle orientation. CONCLUSIONS: There is clinically important asymmetry in the morphologic features of pedicles in individuals with adolescent idiopathic scoliosis. The concave side of the curve compared with the convex side is smaller in height and width periapically. Furthermore, the trajectory of the pedicle is more acute on the convex side of the curve compared with the concave side around the apex of the curve. Knowledge of these anatomic variations is essential when performing scoliosis correction surgery to assist with selecting the correct pedicle screw size and trajectory of insertion to reduce the risk of pedicle wall perforation and neurovascular injury.
Asunto(s)
Tomografía Computarizada Multidetector , Escoliosis/diagnóstico por imagen , Columna Vertebral/diagnóstico por imagen , Adolescente , Puntos Anatómicos de Referencia , Niño , Bases de Datos Factuales , Humanos , Imagenología Tridimensional , Variaciones Dependientes del Observador , Tornillos Pediculares , Valor Predictivo de las Pruebas , Interpretación de Imagen Radiográfica Asistida por Computador , Reproducibilidad de los Resultados , Escoliosis/cirugía , Índice de Severidad de la Enfermedad , Programas Informáticos , Fusión Vertebral/instrumentación , Columna Vertebral/cirugía , Toracoscopía , Adulto JovenRESUMEN
PURPOSE: Cadaveric studies have previously documented a typical pattern of venous drainage within vertebral bodies (VBs), comprised primarily of the basivertebral vein. These studies, however, are limited by the number of samples available. MRI is able to provide 3D images of soft tissue structures in the spine, including the basivertebral vein without the use of contrast in both healthy controls and subjects with abnormal anatomy such as adolescent idiopathic scoliosis (AIS). This study aimed to quantify the venous networks within VBs of 15 healthy adolescent controls and 15 AIS patients. METHODS: Five transverse slices through the VBs were examined simultaneously and the observable vascular network traced. The length of the network on the left and right sides of the VB was calculated, and the spatial patterning assessed level-by-level within each subject. RESULTS: Significant differences were seen in the left/right distribution of vessels in both the control and AIS subjects, with both groups having greater length on the right side of all of their VBs. No difference was seen between AIS and control subjects in any region. Large individual variations in patterns were seen in both groups; however, the control group showed more consistent spatial patterning of the vascular networks across levels in comparison to the AIS group. CONCLUSION: The length of the basivertebral vein was seen to have a significant bias to the right hand side of the VB in both healthy and AIS adolescents. The spatial pattern of this vein showed large variations in branching both within and across individuals. No significant differences were seen between AIS and control subjects, suggesting both that this network is preserved in deformed AIS vertebrae, and that the vertebral venous system does not play a role in the etiology of AIS.
Asunto(s)
Variación Anatómica , Vértebras Lumbares/irrigación sanguínea , Escoliosis/diagnóstico por imagen , Vértebras Torácicas/irrigación sanguínea , Venas/anatomía & histología , Adolescente , Niño , Humanos , Imagenología Tridimensional , Vértebras Lumbares/diagnóstico por imagen , Imagen por Resonancia Magnética , Vértebras Torácicas/diagnóstico por imagen , Venas/diagnóstico por imagenRESUMEN
PURPOSE: We develop a sheep thoracic spine interbody fusion model to study the suitability of polycaprolactone-based scaffold and recombinant human bone morphogenetic protein-2 (rhBMP-2) as a bone graft substitute within the thoracic spine. The surgical approach is a mini-open thoracotomy with relevance to minimally invasive deformity correction surgery for adolescent idiopathic scoliosis. To date there are no studies examining the use of this biodegradable implant in combination with biologics in a sheep thoracic spine model. METHODS: In the present study, six sheep underwent a 3-level (T6/7, T8/9 and T10/11) discectomy with randomly allocated implantation of a different graft substitute at each of the three levels: (a) calcium phosphate (CaP) coated polycaprolactone-based scaffold plus 0.54 µg rhBMP-2 (b) CaP-coated PCL-based scaffold alone or (c) autograft (mulched rib head). Fusion was assessed at 6 months post-surgery. RESULTS: Computed Tomographic scanning demonstrated higher fusion grades in the rhBMP-2 plus PCL-based scaffold group in comparison with either PCL-based scaffold alone or autograft. These results were supported by histological evaluations of the respective groups. Biomechanical testing revealed significantly higher stiffness for the rhBMP-2 plus PCL-based scaffold group in all loading directions in comparison with the other two groups. CONCLUSION: The results of this study demonstrate that rhBMP-2 plus PCL-based scaffold is a viable bone graft substitute, providing an optimal environment for thoracic interbody spinal fusion in a large animal model.
Asunto(s)
Proteína Morfogenética Ósea 2/administración & dosificación , Sustitutos de Huesos/administración & dosificación , Discectomía/métodos , Poliésteres/química , Factor de Crecimiento Transformador beta/administración & dosificación , Implantes Absorbibles , Animales , Sustitutos de Huesos/química , Fosfatos de Calcio/química , Humanos , Masculino , Proteínas Recombinantes/administración & dosificación , Escoliosis/patología , Escoliosis/cirugía , Ovinos , Fusión Vertebral/métodos , Vértebras Torácicas/cirugía , Andamios del Tejido/química , Trasplante AutólogoRESUMEN
PURPOSE: Identification of adolescent idiopathic scoliosis (AIS) patients with mild curvatures who pose significant risk of progressing to severe levels of curvatures is of paramount importance for clinical care. This study aimed to compare segmental deformity changes in AIS sub-cohorts that are dichotomised by progression status. METHODS: Thirty-six female participants with Lenke 1 AIS curves were investigated with sequential MRIs during growth. Scans were reformatted to measure orthogonal segmental parameters, including sagittal/coronal wedging angles and axial rotation angles. Participants were dichotomised by progression. Two-tailed, independent sample t-tests were used to compare sub-cohort multi-segmental and segmental deformity parameters. Measurements were compared at each scan number and variable rates of change were determined using actual time between measures. RESULTS: AIS progression status sub-cohorts were comparable at scan 1 for multi-segmental deformity parameters (e.g. major thoracic curve angle, rib hump, kyphosis) (P > 0.05). However, apical measures of coronal IVD wedging, axial IVD rotation and axial vertebral rotation were segmental parameters at scan 1 which were larger for participants whose AIS would later go on to clinically progress (all P < 0.05). Measures of segmental hypokyphosis were comparable between groups. As development was tracked at each subsequent scan, coronal and axial plane differences between groups increased in both magnitude and number of differences. CONCLUSION: Initial disparity and then subsequent increasing magnitude of change of axial rotation may indicate a higher propensity to clinically progress in the future. This knowledge hopes to provide useful management information for AIS care providers and prognostic education for patients alike. LEVEL OF EVIDENCE: II.
Asunto(s)
Progresión de la Enfermedad , Imagen por Resonancia Magnética , Escoliosis , Humanos , Escoliosis/diagnóstico por imagen , Femenino , Adolescente , Cifosis/diagnóstico por imagen , Cifosis/etiología , Niño , Columna Vertebral/diagnóstico por imagen , Columna Vertebral/anomalías , Estudios de Cohortes , Vértebras Torácicas/diagnóstico por imagenRESUMEN
An accurate estimation of maximal voluntary muscle activation is critical for normalisation in scientific studies. Only a handful of studies appropriately normalise muscle activation data when investigating paraspinal muscle activity in populations such as adolescent idiopathic scoliosis (AIS). This neglect compromises the ability to interpret data. The aim of this study was to determine the type of trunk extension task that reliably achieves peak paraspinal muscle activation in participants with and without AIS. Adolescent females with typically developing spines (controls: n = 20, mean[SD] age 13.1[1.8]years), or primary right thoracic AIS (n = 24, age: 13.8[1.5]years, Cobb angle thoracic: 39.5[16.4]°, lumbar: 28.0[11.6]°) performed a series of 3x unresisted and 3x resisted maximal voluntary trunk extensions in prone. Paraspinal muscle activation was recorded bilaterally at two thoracic levels and one lumbar level using surface electromyography (EMG). Muscle activation was highly repeatable within task [ICC 0.77-0.95, all p < 0.01]. At group level, there were no differences in peak muscle activation between tasks irrespective of side (left/right) or vertebral level (Estimate 0.98, 95%CI 0.36 to 2.65, p=0.97). Peak activation was achieved with the unresisted task in 40.5%, and resisted task in 59.5% of the total outcomes (6 recording locations, 44 participants). Individual participant maximum amplitude varied up to 64% (mean[SD]:18[13]%) between the unresisted and resisted tasks. We recommend that both the resisted and unresisted trunk extension tasks are used to increase confidence that a maximum voluntary activation of paraspinal muscles is achieved. Failure to do so could introduce large error in the estimations of muscle activation.
Asunto(s)
Electromiografía , Músculos Paraespinales , Escoliosis , Humanos , Escoliosis/fisiopatología , Femenino , Adolescente , Músculos Paraespinales/fisiología , Electromiografía/métodos , Contracción Muscular/fisiología , NiñoRESUMEN
INTRODUCTION: 3D Non-Contact surface scanning (3DSS) is used in both biomechanical and clinical studies to capture accurate 3D images of the human torso, and to better understand the shape and posture of the spine-both healthy and pathological. This study sought to determine the efficacy and accuracy of using 3DSS of the posterior torso, to determine the curvature of the spinal column in the lateral lying position. METHODS: A cohort of 50 healthy adults underwent 3DSS and Magnetic Resonance Imaging (MRI) to correlate the contours of the external spine surface with the internal spinal column. The correlation analysis was composed of two phases: (1) MRI vertebral points vs MRI external spine surface markers; and (2) MRI external spine surface markers vs 3DSS external spine surface markers. The first phase compared the profiles of fiducial markers (vitamin capsules) adhered to the skin surface over the spinous processes against the coordinates of the spinous processes-assessing the linear distance between the profiles, and similarity of curvature, in the sagittal and coronal planes. The second phase compared 3DSS external spine surface markers with the MRI external spine surface markers in both planes, with further qualitative assessment for postural changes. RESULTS: The distance between the MRI vertebral points and MRI external spine surface markers showed strong statistically significant correlation with BMI in both sagittal and coronal planes. Kolmogorov-Smirnov (KS) tests showed similar no significant difference in curvature, k, in almost all participants on both planes. In the second phase, the coronal 3DSS external spine surface profiles were statistically different to the MRI external spine surface markers in 44% of participants. Qualitative assessment showed postural changes between MRI and 3DSS measurements in these participants. CONCLUSION: These study findings demonstrate the utility and accuracy of using anatomical landmarks overlaid on the spinous processes, to identify the position of the spinal bones using 3DSS. Using this method, it will be possible to predict the internal spinal curvature from surface topography, provided that the thickness of the overlaying subcutaneous adipose layer is considered, thus enabling postural analysis of spinal shape and curvature to be carried out in biomechanical and clinical studies without the need for radiographic imaging.
Asunto(s)
Escoliosis , Curvaturas de la Columna Vertebral , Adulto , Humanos , Escoliosis/diagnóstico por imagen , Columna Vertebral/diagnóstico por imagen , Curvaturas de la Columna Vertebral/diagnóstico por imagen , Radiografía , TorsoRESUMEN
Adolescent Idiopathic Scoliosis (AIS) is a 3D spine deformity that also causes ribcage and torso distortion. While clinical metrics are important for monitoring disorder progression, patients are often most concerned about their cosmesis. The aim of this study was to automate the quantification of AIS cosmesis metrics, which can be measured reliably from patient-specific 3D surface scans (3DSS). An existing database of 3DSS for pre-operative AIS patients treated at the Queensland Children's Hospital was used to create 30 calibrated 3D virtual models. A modular generative design algorithm was developed on the Rhino-Grasshopper software to measure five key AIS cosmesis metrics from these models-shoulder, scapula and hip asymmetry, torso rotation and head-pelvis shift. Repeat cosmetic measurements were calculated from user-selected input on the Grasshopper graphical interface. InterClass-correlation (ICC) was used to determine intra- and inter-user reliability. Torso rotation and head-pelvis shift measurements showed excellent reliability (> 0.9), shoulder asymmetry measurements showed good to excellent reliability (> 0.7) and scapula and hip asymmetry measurements showed good to moderate reliability (> 0.5). The ICC results indicated that experience with AIS was not required to reliably measure shoulder asymmetry, torso rotation and head-pelvis shift, but was necessary for the other metrics. This new semi-automated workflow reliably characterises external torso deformity, reduces the dependence on manual anatomical landmarking, and does not require bulky/expensive equipment.
Asunto(s)
Cosméticos , Cifosis , Escoliosis , Niño , Humanos , Adolescente , Escoliosis/cirugía , Reproducibilidad de los Resultados , Torso , HombroRESUMEN
PURPOSE: Vertebral body tethering (VBT) is a recent procedure to correct and reduce spinal curves in skeletally immature patients with adolescent idiopathic scoliosis (AIS). The purpose of this systematic review and meta-analysis is to determine the expected curve reduction and potential complications for adolescent patients after VBT. METHODS: PubMed, Embase, Google Scholar and Cochrane databases were searched until February 2022. Records were screened against pre-defined inclusion and exclusion criteria. Data sources were prospective and retrospective studies. Demographics, mean differences in Cobb angle, surgical details and complication rates were recorded. Meta-analysis was conducted using a random-effects model. RESULTS: This systematic review includes 19 studies, and the meta-analysis includes 16 of these. VBT displayed a statistically significant reduction in Cobb angle from pre-operative to final (minimum 2 years) measurements. The initial mean Cobb angle was 47.8° (CI 95% 42.9-52.7°) and decreased to 22.2° (CI 95% 19.9-24.5°). The mean difference is - 25.8° (CI 95% - 28.9-22.7) (p < 0.01). The overall complication rate was 23% (CI 95% 14.4-31.6%), the most common complication was tether breakage 21.9% (CI 95% 10.6-33.1%). The spinal fusion rate was 7.2% (CI 95% 2.3-12.1%). CONCLUSION: VBT results in a significant reduction of AIS at 2 years of follow-up. Overall complication rate was relatively high although the consequences of the complications are unknown. Further research is required to explore the reasons behind the complication rate and determine the optimal timing for the procedure. VBT remains a promising new procedure that is effective at reducing scoliotic curves and preventing spinal fusion in the majority of patients. LEVEL OF EVIDENCE: Systematic review of Therapeutic Studies with evidence level II-IV.
RESUMEN
STUDY DESIGN: A prospective cohort study. OBJECTIVE: Detail typical three-dimensional segmental deformities and their rates of change that occur within developing adolescent idiopathic scoliosis (AIS) spines over multiple timepoints. SUMMARY OF BACKGROUND DATA: AIS is a potentially progressive deforming condition that occurs in three dimensions of the scoliotic spine during periods of growth. However, there remains a gap for multiple timepoint segmental deformity analysis in AIS cohorts during development. MATERIALS AND METHODS: Thirty-six female patients with Lenke 1 AIS curves underwent two to six sequential magnetic resonance images. Scans were reformatted to produce images in orthogonal dimensions. Wedging angles and rotatory values were measured for segmental elements within the major curve. Two-tailed, paired t tests compared morphologic differences between sequential scans. Rates of change were calculated for variables given the actual time between successive scans. Pearson correlation coefficients were determined for multidimensional deformity measurements. RESULTS: Vertebral bodies were typically coronally convexly wedged, locally lordotic, convexly axially rotated, and demonstrated evidence of local mechanical torsion. Between the first and final scans, apical measures of coronal wedging and axial rotation were all greater in both vertebral and intervertebral disk morphology than nonapical regions (all reaching differences where P <0.05). No measures of sagittal deformity demonstrated a statistically significant change between scans. Cross-planar correlations were predominantly apparent between coronal and axial planes, with sagittal plane parameters rarely correlating across dimensions. Rates of segmental deformity changes between earlier scans were characterized by coronal plane convex wedging and convexly directed axial rotation. The major locally lordotic deformity changes that did occur in the sagittal plane were static between scans. CONCLUSIONS: This novel investigation documented a three-dimensional characterization of segmental elements of the growing AIS spine and reported these changes across multiple timepoints. Segmental elements are typically deformed from initial presentation, and subsequent changes occur in separate orthogonal planes at unique times.
Asunto(s)
Cifosis , Lordosis , Escoliosis , Humanos , Adolescente , Femenino , Escoliosis/patología , Estudios Prospectivos , Vértebras Torácicas/patología , Vértebras Lumbares/patología , Imagen por Resonancia Magnética/métodos , Lordosis/patología , Cifosis/patología , Imagenología Tridimensional/métodosRESUMEN
BACKGROUND: Adolescent idiopathic scoliosis is a common condition affecting 2.5% of the general population. Vertebral body stapling was introduced as a method of fusionless growth modulation for the correction of moderate idiopathic scoliosis (Cobb angles of 20-40°), and was claimed to be more effective than bracing and less invasive than fusion. The aim of this study was to assess the effect of vertebral body stapling on the stiffness of a thoracic motion segment unit under moment controlled load, and to assess the vertebral structural damage caused by the staples. METHODS: Thoracic spine motion segments from 6 to 8 week old calves (n=14) were tested in flexion/extension, lateral bending, and axial rotation. The segments were tested un-instrumented, then a left anterolateral intervertebral Shape Memory Alloy (SMA) staple was inserted and the test was repeated. Data were collected from the tenth load cycle of each sequence and stiffness was calculated. The staples were carefully removed and the segments were studied with micro-computed tomography to assess physical damage to the bony structure. Visual assessment of the vertebral bone structure on micro-CT was performed. FINDINGS: There was no change in motion segment stiffness in flexion/extension nor in axial rotation. There was a reduction in stiffness in lateral bending with 30% reduction bending away from the staple and 12% reduction bending towards the staple. Micro-CT showed physeal damage in all the specimens. INTERPRETATION: Intervertebral stapling using SMA staples cause a reduction in spine stiffness in lateral bending. They also cause damage to the endplate epiphyses.
Asunto(s)
Fenómenos Mecánicos , Cuerpo Vertebral/fisiología , Adolescente , Animales , Fenómenos Biomecánicos , Bovinos , Humanos , Rotación , Suturas , Cuerpo Vertebral/anatomía & histología , Cuerpo Vertebral/diagnóstico por imagen , Cuerpo Vertebral/cirugía , Soporte de Peso , Microtomografía por Rayos XRESUMEN
STUDY DESIGN: Cross-sectional study. OBJECTIVES: To provide a comprehensive, multi-stage investigation of vertebral body (VB) and intervertebral disc (IVD) coronal plane deformities for adolescent idiopathic scoliosis (AIS) patients with a main thoracic curve type, using a series of sequential magnetic resonance images (MRIs). Despite numerous investigations of AIS deformity at the spinal segmental level, there is little consensus as to the major contributor to the lateral curvature of a scoliotic spine. Moreover, scoliotic deformity is often described along a continuum of progression, with few studies having characterised the change in segmental deformity for AIS patients whose deformity progresses clinically over time. METHODS: 30 female AIS patients with primary thoracic curves were included between 2012 and 2016. Three sequential MRIs were captured for each patient. Datasets were reformatted to produce true coronal plane images of the thoracic spine (T4-L1). Overall curve morphology, coronal plane IVD and VB segmental deformity and rates of growth were analysed. RESULTS: Right-side asymmetry was greater in IVDs (18.5 ± 23.9%) when compared to VBs (8.3 ± 9.2%) (P < 0.05) by third scans. Despite this, 77% of patients demonstrated the majority (> 50%) of their coronal curvature was attributed to VB wedging when measured across all three scans. Regardless of progression status, scan number, or region, the sum of the VB wedging angle was greater than the sum of the IVD wedging angle (all P ≤ 0.05). There was no correlation between the rates of major curve angle progression and standing height increase, VB height growth, or IVD height growth (P > 0.05). CONCLUSIONS: VB wedging contributed more to the lateral deformity observed in primary thoracic subtypes of AIS patients than IVD wedging. While IVDs demonstrated the greatest asymmetric deformity, their relatively smaller height resulted in a smaller proportional change in lateral curve angle compared to the VBs. LEVEL OF EVIDENCE: IV.
Asunto(s)
Disco Intervertebral/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Escoliosis/diagnóstico por imagen , Vértebras Torácicas/anomalías , Vértebras Torácicas/diagnóstico por imagen , Adolescente , Niño , Estudios Transversales , Femenino , Humanos , Disco Intervertebral/crecimiento & desarrollo , Masculino , Vértebras Torácicas/crecimiento & desarrolloRESUMEN
STUDY DESIGN: Prospective cohort study. OBJECTIVES: Investigate the progressive changes in pedicle morphometry and the spatial relationship between the pedicles and neurovascular structures in patients with AIS during growth. Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional spine deformity. AIS pedicles are known to be asymmetrical when compared to adolescents without scoliosis. Defining the anatomical changes occurring progressively in scoliosis as it increases with time and growth is essential for understanding the pathophysiology of scoliosis and for treatment planning. MRI is the ideal method to study the growing spine without ionising radiation. METHODS: 24 females with AIS (mean 12.6 years, right sided main thoracic curves) and 20 non-scoliotic females (mean 11.5 years) were selected from an ongoing database. Participants underwent two 3D MRI scans (3 T scanner, T1, 0.5 mm isotropic voxels) approximately 1 year apart (AIS: mean 1.3 ± 0.05 years, control: mean 1.0 ± 0.1 years). The pedicle width, chord length, pedicle height, transverse pedicle angle, sagittal pedicle angle, distance from vertebrae to aorta and distance from pedicle to dural sac were measured from T5 to T12. Inter- and intra-observer variability was assessed. RESULTS: From scans 1-2 in the AIS group, the dural sac became closer to the left pedicle (p < 0.05, T6, T8-T10 and T12) while the distance from the vertebrae to the aorta increased (p < 0.05, T6-T10). No significant changes in these measurements were observed in the non-scoliotic group. Between scans, the AIS chord length and transverse pedicle angle increased on the left side around the apex (p < 0.05) creating asymmetries not seen in the non-scoliotic cohort. The mean pedicle height increased symmetrically in the non-scoliosis cohort (p < 0.05) and asymmetrically in the AIS group with the right side growing faster than the left at T6-T7 (p < 0.05). CONCLUSION: Asymmetrical growth patterns occur in the vertebral posterior elements of AIS patients compared to the symmetrical growth patterns found in the non-scoliotic participants. LEVEL OF EVIDENCE: Level II prospective comparative study.
Asunto(s)
Escoliosis/patología , Cuerpo Vertebral/crecimiento & desarrollo , Cuerpo Vertebral/patología , Adolescente , Factores de Edad , Niño , Progresión de la Enfermedad , Femenino , Humanos , Imagenología Tridimensional , Imagen por Resonancia Magnética , Estudios Prospectivos , Escoliosis/diagnóstico por imagen , Cuerpo Vertebral/anatomía & histología , Cuerpo Vertebral/diagnóstico por imagenRESUMEN
INTRODUCTION: 3D non-contact surface scanners capture highly accurate, calibrated images of surface topography for 3D structures. This study sought to establish the efficacy and accuracy of using 3D surface scanning to characterise spinal curvature and sagittal plane contour. METHODS: 10 healthy female adults with a mean age of 25 years, (standard deviation: 3.6 years) underwent both MRI and 3D surface scanning (3DSS) (Artec Eva, Artec Group Inc., Luxembourg) while lying in the lateral decubitus position on a rigid substrate. Prior to 3DSS, anatomical landmarks on the spinous processes of each participant were demarcated using stickers attached to the skin surface. Following 3DSS, oil capsules (fiducial markers) were overlaid on the stickers and the subject underwent MRI. MRI stacks were processed to measure the thoracolumbar spinous process locations, providing an anatomical reference. 3D coordinates for the markers (surface stickers and MRI oil capsules) and for the spinous processes mapped the spinal column profiles and were compared to assess the quality of fit between the 3DSS and MRI marker positions. RESULTS: The RMSE for the polynomials fit to the spinous process, fiducial and surface marker profiles ranged from 0.17-1.15mm for all subjects. The MRI fiducial marker location was well aligned with the spinous process profile in the thoracic and upper lumbar spine for nine of the subjects. Over the 10 subjects, the mean RMSE between the MRI and 3D scan sagittal profiles for all surface markers was 9.8mm (SD 4.2mm). Curvature was well matched for seven of the subjects, with two showing differing curvatures across the lumbar spine due to inconsistent subject positioning. CONCLUSION: Comparison of the observed trends for vertebral position measured from MRI and 3DSS, suggested the surface markers may provide a useful method for measuring internal changes in sagittal curvature or skeletal changes.
Asunto(s)
Imagen por Resonancia Magnética , Columna Vertebral/diagnóstico por imagen , Adulto , Puntos Anatómicos de Referencia/anatomía & histología , Puntos Anatómicos de Referencia/diagnóstico por imagen , Dorso/anatomía & histología , Dorso/diagnóstico por imagen , Femenino , Humanos , Imagenología Tridimensional/métodos , Imagen por Resonancia Magnética/métodos , Curvaturas de la Columna Vertebral/diagnóstico por imagen , Columna Vertebral/anatomía & histologíaRESUMEN
OBJECTIVES: Lemierre's syndrome cause by methicillin-sensitive Staphylococcus aureus is rare, but can lead to necrotizing pneumonia and septicaemia. When treating such patient with extracorporeal life support source control can be both challenging and controversial. METHODS: In this report we present a 12 year old male who presented with Lemierre's syndrome from which he developed septic shock and severe necrotizing pneumonia. He also showed multiple pulmonary embolisms from the internal jugular vein thrombi, resulting in acute respiratory distress syndrome. RESULTS: The patient was treated with extracorporeal life support. Subsequent computed tomography revealed multiple abscesses throughout his lungs and around vertebral bodies C1 and C2, for which source control with drainage of the cervical abscesses was achieved while on extracorporeal life support. The necrotizing pneumonia gradually improved, and partial pneumectomy was avoided. He was successfully separated from extracorporeal life support and respiratory support and recovered from his illness. Follow-up imaging showed almost complete resolution of the pulmonary abscesses. Osteomyelitis of C1/C2 and severe muscle wasting required a prolonged hospital stay. CONCLUSION: This case highlights the challenges of supporting patients suffering from disseminated staphylococcal sepsis with extracorporeal life support and the key role of source control and demonstrates the value of using extracorporeal life support in necrotizing pneumonia.
RESUMEN
STUDY DESIGN: Lung volumes and thoracic anatomy were measured from low-dose computed tomography (CT) scans preoperatively and 2 years following thoracoscopic anterior spinal fusion (TASF) for adolescent idiopathic scoliosis (AIS). OBJECTIVE: The aim of this study was to assess changes in lung volume after TASF surgical correction. SUMMARY OF BACKGROUND DATA: AIS patients are known to have decreased pulmonary function as a consequence of their spinal and ribcage deformity. Several studies have evaluated changes in pulmonary function clinically after scoliosis correction surgery showing varied results. To date, there have been no published studies using CT to evaluate lung volume changes following TASF. METHODS: Twenty-three female AIS patients with both pre- and 2 years postoperative low-dose CT scans were selected from an ethically approved, historical databank. Three-dimensional lung volumes were reconstructed to determine anatomical lung volumes. Right and left lung volumes, total lung volume, and right-to-left lung volume ratio were obtained as well as hemithoracic symmetry, to indicate the extent of thorax deformity. Cobb angle, rib hump, levels fused in surgery, and patient height were used for correlation analysis with the lung volume results. RESULTS: Left lung volume, total lung volume, and hemithoracic ratio all increased significantly 2 years after surgery. There was no significant change in right-to-left lung volume ratio (Pâ=â0.36). Statistical regression found significant positive correlation between lung volume changes, reduction in Cobb angle, increase in height, and improvement in hemithoracic symmetry ratio. CONCLUSION: TASF resulted in a statistically significant increase in lung volume following surgery, as well as improvement in the symmetry of the thoracic architecture; however, the postoperative lung volumes remained in the lower 50th percentile relative to females without thoracic deformity. Furthermore, change in lung volume was significantly correlated with changes in Cobb angle, hemithoracic asymmetry, and increased patient height, which are important consequences of thoracic deformity correction surgery. LEVEL OF EVIDENCE: 3.
Asunto(s)
Pulmón/diagnóstico por imagen , Escoliosis/cirugía , Fusión Vertebral/métodos , Vértebras Torácicas/cirugía , Toracoscopía , Tórax/diagnóstico por imagen , Adolescente , Femenino , Humanos , Imagenología Tridimensional , Pulmón/patología , Tamaño de los Órganos , Periodo Posoperatorio , Tórax/patología , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND CONTEXT: In recent years, there has been increasing appreciation of the need to treat scoliosis as a three-dimensional deformity. PURPOSE: Assessment of surgical strategies and outcomes should consider not only the coronal plane correction but also derotation of the transverse plane deformity that can affect trunk appearance. STUDY DESIGN: This study included a cohort of 29 female adolescent idiopathic scoliosis patients who received thoracoscopic single rod anterior fusion (TASF) surgery. This study used pre- and postoperative low-dose computed tomographic (CT) scans to accurately measure apical axial vertebral rotation (AVR). METHODS: The pre- and postoperative values for clinically measured coronal Cobb correction and rib hump correction as well as AVR were compared to determine whether these values improved postoperatively. There are no conflicts of interest to report for authors of this investigation. RESULTS: As expected, statistically significant reductions in coronal Cobb angle (mean preoperative Cobb 51°, reducing to 24° at the two-year follow-up) and rib hump (mean preoperative rib hump 15°, reducing to 7° at two-year follow-up) were achieved. The mean reduction in apical AVR measured using CT was only 3° (mean preoperative AVR 16°, reducing to 13° at two-year follow-up), which was statistically but not clinically significant. Significant correlations were found between Cobb angle and rib hump, between Cobb angle and AVR, and between AVR and rib hump, suggesting that patients with greater coronal Cobb correction also achieve better derotation with this surgical procedure. CONCLUSIONS: The historical low-dose CT data set permitted detailed three-dimensional assessment of the deformity correction that is achieved using thoracoscopic anterior spinal fusion for progressive adolescent idiopathic scoliosis.